Multimodal polyalkylene terephthalate

Abstract

A method of forming a multimodal Polyalkylene Terephthalate (PAT) can include: providing a feed of a low molecular weight (LMW) PAT, the LMW PAT having a low average molecular weight; providing a feed of high molecular weight (HMW) PAT, the HMW PAT having a high average molecular weight, wherein the low average molecular weight is lower than the high average molecular weight; mixing the feed of LMW PAT with the feed of HMW PAT in a mixer to form a multimodal PAT; and providing the multimodal PAT as output. The multimodal PAT can include: a low average molecular weight of a low molecular weight (LMW) PAT; and a high average molecular weight of a high molecular weight (HMW) PAT mixed with the LMW PAT to form the multimodal PAT, wherein the multimodal PAT is devoid of talc.

The invention claimed is: 
     
       1. A method of forming a multimodal Polyalkylene Terephthalate (PAT), the method comprising:
 providing a feed of a low molecular weight (LMW) PAT, the LMW PAT having a low average molecular weight and having a degrading molecule selected from the group consisting of water, alcohol, diol, polyol, thiol, dithiol, polythiol, amine, and combinations thereof; 
 providing a feed of high molecular weight (HMW) PAT, the HMW PAT having a high average molecular weight, wherein the low average molecular weight is lower than the high average molecular weight; 
 mixing the feed of LMW PAT with the feed of HMW PAT in a mixer to form a multimodal PAT; and 
 providing the multimodal PAT as output, wherein the multimodal PAT includes the degrading molecule. 
 
     
     
       2. The method of  claim 1 , wherein the LMW PAT and/or HMW PAT is devoid of talc or other particles. 
     
     
       3. The method of  claim 1 , wherein the HMW PAT is recycled HMW PAT. 
     
     
       4. The method of  claim 1 , further comprising:
 providing the LMW PAT having a characteristic of at least one of: an intrinsic viscosity of about 0.4 to about 0.6; a melting point of about 240° C. to about 247° C.; or a glass transition temperature of about 70° C. to about 80° C.; and/or 
 providing the HMW PAT having a characteristic of at least one of: an intrinsic viscosity of about 0.7 to about 0.85; a melting point of about 245° C. to about 255° C.; or a glass transition temperature of about 75° C. to about 85° C. 
 
     
     
       5. The method of  claim 1 , wherein the multimodal PAT includes the LMW PAT at about 10% to about 50% by weight of the multimodal PAT. 
     
     
       6. The method of  claim 5 , wherein the multimodal PAT includes the LMW PAT at about 30% to about 35% by weight of the multimodal PAT. 
     
     
       7. The method of  claim 1 , further comprising:
 obtaining the multimodal PAT having a characteristic of at least one of: an intrinsic viscosity of about 0.45 to about 0.65; a melting point of about 245° C. to about 248° C.; or a glass transition temperature of about 77° C. to about 81° C. 
 
     
     
       8. The method of  claim 1 , wherein the multimodal PAT has the degrading molecule at an amount of about 0.1% to about 0.3% by weight. 
     
     
       9. The method of  claim 1 , further comprising forming the low molecular weight polyalkylene terephthalate (PAT) by:
 providing a second feed of a second high molecular weight (second HMW) PAT, the second HMW PAT having a high average molecular weight; 
 providing a feed of the degrading molecule; 
 reacting the second HMW PAT with the degrading molecule in a reactor; 
 degrading the second HMW PAT with the degrading molecule into low molecular weight (LMW PAT) having a low average molecular weight that is lower than the high average molecular weight; and 
 providing the LMW PAT as output. 
 
     
     
       10. The method of  claim 9 , wherein the degrading molecule cleaves polymer chains of the second HMW PAT into smaller polymer chains that contain reaction products of the second HMW PAT and a degrading molecule. 
     
     
       11. The method of  claim 10 , wherein at least a portion of the degrading molecule is unreacted and present in the LMW PAT. 
     
     
       12. The method of  claim 9 , wherein the degrading molecule is selected from:
 water; 
 an alcohol selected from methanol, ethanol, propanol, isopropanol, butanol, n-butanol, isobutanol, tertbutanol, or combinations thereof: 
 a diol selected from ethylene glycol, butanediol, propylene-1,3-diol, beta propylene glycol, methanediol, propane-1,2-diol, alpha propylene glycol, or combinations thereof; 
 a polyol selected from xylitol, pentaerythritol, maltitol, sorbitol, isomalt, lactitol, mannitol, glycerol, trimethylolpropane, polyethylene glycol, or combinations thereof; 
 a thiol selected from methanthiol, ethanthiol, propanthiol, isopropanthiol, butanthiol, n-butanthiol, isobutanthiol, tertbutanthiol, or combinations thereof; 
 a dithiol selected from methanedithiol, 1,1-ethanedithiol, and 1,1-cyclohexanedithiol, 1,3-propanedithiol, dithiothreitol, and combinations thereof; 
 a polythiol selected from a polymer having a plurality of monomers having a thiol; or 
 an amine selected from methylamine, dimethylamine, trimethylamine, ethylamine, aniline, 4-methoxyaniline, N,N-dimethylaniline, 3-nitroaniline, 4-nitroaniline, 4-trifluoromethylaniline, and combinations thereof. 
 
     
     
       13. The method of  claim 9 , wherein the degrading molecule is not talc or other particle, and thereby the LMW PAT is devoid of particles. 
     
     
       14. The method of  claim 9 , further comprising characterizing the LMW PAT to have at least one of:
 an intrinsic viscosity of about 0.4 to about 0.6; 
 a melting point of about 240° C. to about 247° C.; 
 a glass transition temperature of about 70° C. to about 80° C. 
 
     
     
       15. The method of  claim 9 , wherein the degrading molecule is provided in an amount so that about 0.25% to about 5% by weight of the second HMW PAT is degraded. 
     
     
       16. The method of  claim 9 , wherein the second HMW PAT has a characteristic of at least one of:
 an intrinsic viscosity of about 0.7 to about 0.85; 
 a melting point of about 245° C. to about 255° C.; or 
 a glass transition temperature of about 75° C. to about 85° C. 
 
     
     
       17. The method of  claim 9 , wherein the method is performed with a system comprising:
 a feed line having second high molecular weight (second HMW) PAT, the second HMW PAT having a high average molecular weight; 
 a feedline a of degrading molecule; 
 a reactor having the second HMW PAT with the degrading molecule; and 
 an output having low molecular weight (LMW PAT) with a low average molecular weight that is lower than the high average molecular weight. 
 
     
     
       18. The method of  claim 1 , wherein the method is performed with a system comprising:
 a feed of the low molecular weight (LMW) PAT, the LMW PAT having a low average molecular weight; 
 a feed of a second high molecular weight (second HMW) PAT, the second HMW PAT having a high average molecular weight, wherein the low average molecular weight is lower than the high average molecular weight; 
 a mixer having the LMW PAT and second HMW PAT; and 
 an output having the multimodal PAT. 
 
     
     
       19. The method of  claim 1 , further comprising characterizing the multimodal PAT by:
 a low average molecular weight of the low molecular weight (LMW) PAT; 
 a high average molecular weight of the high molecular weight (HMW) PAT mixed with the LMW PAT to form the multimodal PAT, 
 wherein the multimodal PAT is devoid of talc. 
 
     
     
       20. The method of  claim 1 , wherein the LMW PAT is at about 10% to about 50% by weight of the multimodal PAT. 
     
     
       21. The method of  claim 1 , further comprising the multimodal PAT having a characteristic of:
 an intrinsic viscosity of about 0.45 to about 0.75; 
 a melting point of about 245° C. to about 248° C.; and 
 a glass transition temperature of about 77° C. to about 81° C.